Torque sensors and power controls were developed in the late 1990s. For example, Takada Yutky of Japan filed a patent in 1997 for such a device. In 1992 Vector Services Limited offered and sold an electric bicycle dubbed Zike. The bicycle included Nickel-cadmium batteries that were built into a frame member and included an 850 g permanent-magnet motor. Despite the Zike, in 1992 hardly any commercial electric bicycles were available. It wasn’t until 1998 when there were at least 49 different bikes. Production grew from 1993 to 2004 by an estimated 35%. By Contrast, according to Gardner, in 1995 regular bicycle production decreased from its peak 107 million units. Some of the less expensive electric bicycles used bulky lead acid batteries, whereas newer models generally used NiMH, NiCd and/or Li-ion batteries which offered lighter, denser capacity batteries. The end benefits usually varied from manufacturer; however, in general there was an increase in range and speed. By 2004 electric bicycles where manufactured by Currie Technologies, EV Global, Optibike, Giante Lite, Merida, ZAP.
Massachusetts General Laws define three classes of motorized two-wheeled vehicles: Motorcycle, Motorized bicycle, and Motorized scooter. Although the definition of motorized scooter includes two-wheeled vehicles propelled by electric motors with or without human power, motorized scooter specifically excludes anything which falls under the definitions of motorized bicycle and motorcycle. Motorized bicycle is a pedal bicycle which has a helper motor, or a non-pedal bicycle which has a motor, with a cylinder capacity not exceeding fifty cubic centimeters, an automatic transmission, and which is capable of a maximum speed of no more than thirty miles per hour. Motorcycle includes any bicycle with a motor or driving wheel attached, with the exception of vehicles that fall under the specific definition of motorized bicycle. Thus, a pedal bicycle with an electric motor or a non-pedal bicycle with an electric motor, automatic transmission, and maximum speed of 30 miles an hour would fall under the definition of motorized bicycle. An electric bicycle that did not meet those restrictions would be either a motorized scooter or motorcycle, depending on specific characteristics.